This invention relates to fittings particularly adapted to interconnect the plumbing for a gas turbine engine and its fuel control and particularly to means for angular movement of its elbow for ease of installation.
As is well known in the turbine engine art, size and weight are of paramount importance and it generally is essential to keep them at a minimum. Heretofore, the non-flexible type tubing interconnecting the jet engine and its fuel control required a positioning type or bulkhead fitting which not only required more room than the fitting of this invention but because of their nature had to be carefully installed and precisely adjusted so as not to extrude or damage the cooperating O-ring seal. In the bulkhead type, once the male portion was aligned with the female portion of the connection, a nut had to be torqued which compressed the O-ring seal. Torquing the nut, if the parts were not exactly aligned, the O-ring could be extruded or damaged. The space required to accommodate the O-ring made disassembly difficult.
We have found that in addition to solving the problems noted above the swivel fitting made in accordance with this invention provides greater positioning flexibility than heretofore known fittings as well as improves sealing.
It is contemplated that this swivel fitting carries an adapter with a complimentary O-ring seal that is designed to thread into a boss formed on the fuel control casing. This permits the associated swivel elbow and collar to be readily positioned without disturbing the boss seal.
Additionally, I have found that by virtue of this invention the height from the boss face to the tip of the swivel fitting is less than the corresponding height of the heretofore known positioning type fitting. In certain installations it was found that these fittings permitted fuel control removal which was not readily obtainable heretofore. Hence, by positioning the swivel for allowing elbow removal, the fuel control and its pump could easily be removed from the engine, leaving the tubes in the installed position.